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Insider Cluster (2 insiders) ·Filed Jul 6, 2026

CSTL

CASTLE BIOSCIENCES INC
NEUTRAL
Impact 3/10
Horizondays Processed3mo ago
Insider cluster: 2 insiders, $351K total
Actionable Insight • Neutral

The insider selling is routine and immaterial in size. CEO exercised cheap options and sold to cover — standard practice. No bearish signal. Monitor the next quarterly filing for any fundamental deterioration, but this cluster alone does not warrant action.

DirectionNeutral
Confidencehigh
Horizondays
Final — all horizons settled through T+60d
CSTL ▲ +49.10% at T+60d
NEUTRAL call +49.10% · α vs SPY +47.10% · entry $23.83 → $35.53
Entry = T+0 close
Jul 6, 2026
via day close
T+1d
-0.80%
call -0.80% · α -0.49%
$23.64
settled 4mo ago
T+5d
-2.98%
call -2.98% · α -3.53%
$23.12
settled 4mo ago
T+20d
+30.84%
call +30.84% · α +27.68%
$31.18
settled 3mo ago
T+60d
+49.10%
call +49.10% · α +47.10%
$35.53
settled 28d ago

Price Chart

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Executive Summary

CEO Derek Maetzold and COO Kristen Oelschlager sold a combined $351K in open-market shares on July 1, 2026. The CEO's sales were part of a same-day derivative exercise (6,214 shares at $2.39 strike), making the net open-market sales ~$219K after accounting for the exercise cost. The cluster represents ~0.05% of the $731M market cap, well below the 0.1% materiality threshold, and is consistent with routine tax-related selling following option exercises.

Key Financial Metrics

Direction
selling
Total Value
$361.0K
Insiders
2

Key Facts

  • CEO Derek Maetzold sold 6,214 shares open-market at $24.29 ($151K) on July 1, 2026, after exercising options at $2.39/share
  • COO Kristen Oelschlager sold 8,586 shares open-market at ~$24.40 ($210K) on July 1, 2026
  • Total cluster value: ~$361K in open-market sales, ~0.05% of $731M market cap
  • CEO's derivative exercise of 6,214 shares at $2.39 strike ($14.9K cost) was a non-cash event; the subsequent sale is typical for covering exercise costs and taxes
  • No insider purchases in the cluster; all activity is sell-side

Financial Impact

Total open-market sales of ~$361K, representing ~0.05% of market cap — trivial relative to company size

insider ownership

Risk Factors

  • Insider selling could accelerate if stock continues to rise, but current volume is negligible
  • No fundamental risk signaled by this cluster

Market Snapshot

Exchange
Nasdaq
Sector
Services-Medical Laboratories
Analyst Consensus
93% bullish (14 analysts)

Investment Themes

Documents Analyzed

This report is based on 1 SEC document filed with EDGAR.

DocumentAccession Number
CLUSTER Data (Synthetic)cluster-CSTL-1783408538204
31 reports for CSTL
Performance horizon
60% Hit rate @ T+1 6 of 10 directional calls Went positive at some point 9 of 10 best @ T+60▲ +27.32%Mar 5, 2026
Filters
Rows
Reports for CSTL — sortable, filterable
TypeNow
Oct 21, 2026
5d ago
Insider Cluster
NEUTRAL ★ 3/10
$33.19 $33.08▼ −0.33%▲ +0.19%$33.30 (+0.33%)
Oct 5, 2026
21d ago
144
NEUTRAL ★ 4/10
$33.36 $33.00▼ −1.08%▼ −0.84%$33.30 (−0.18%)
Oct 5, 2026
21d ago
Insider Cluster
NEUTRAL ★ 2/10
$33.36 $33.00▼ −1.08%▼ −0.84%$33.30 (−0.18%)
Sep 23, 2026
4w ago
Insider Cluster
BEARISH ★ 4/10
$35.19 $35.81▼ −1.76%▼ −1.22%$33.30 (+5.37%)
Sep 16, 2026
5w ago
Insider Cluster
NEUTRAL ★ 2/10
$36.78 $35.34▼ −3.92%▼ −4.04%$33.30 (−9.46%)
Sep 11, 2026
6w ago
144
NEUTRAL ★ 4/10
$33.44 $35.50▲ +6.16%▲ +6.62%$33.30 (−0.42%)
Sep 3, 2026
7w ago
Insider Cluster
BEARISH ★ 4/10
$32.91 $32.76▲ +0.46%▼ −0.09%$33.30 (−1.19%)
Sep 2, 2026
7w ago
Insider Cluster
NEUTRAL ★ 2/10
$32.65 $32.91▲ +0.80%▲ +1.18%$33.30 (+1.99%)
Sep 1, 2026
7w ago
Insider Cluster
NEUTRAL ★ 2/10
$33.42 $32.65▼ −2.30%▼ −3.35%$33.30 (−0.36%)
Aug 27, 2026
8w ago
Insider Cluster
NEUTRAL ★ 4/10
$33.50 $33.03▼ −1.40%▼ −1.10%$33.30 (−0.60%)
Showing 10 of 31

US Market Status

Market Closed — Opens in 3h 13m

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Report published Jul 7, 2026